The invention relates to a motor vehicle having a chassis frame and a vehicle body. The chassis frame accommodates the chassis having a front axle and a rear axle. The vehicle body is connected with the chassis frame by way of connection elements.
A motor vehicle of the above-described type is disclosed in EP 0 868 338 B1. However, information on how a self-steering behavior of the known motor vehicle can be influenced is not provided in EP 0 868 338 B1.
It is an object of the invention to further develop the known motor vehicle such that a self-steering behavior of the motor vehicle can be influenced.
This and other objects are achieved by a motor vehicle according to the invention having a chassis frame and a vehicle body. The chassis frame accommodates the chassis having a front axle and a rear axle. The vehicle body is connected with the chassis frame by way of connection elements. The connection elements—viewed in the longitudinal direction of the vehicle—are arranged at a distance from a connection line of the wheel contact points of the wheels of the front and/or rear axle. Viewed in the longitudinal direction of the vehicle, in front of as well as behind the corresponding connection line of the wheel contact points (in each case at least one connection element is provided at the front axle and/or at the rear axle), the transverse rigidity of the connection elements are variable.
A process for influencing the self-steering behavior of the motor vehicle according to the invention changes the transverse rigidity of the at least one connection element in front of and behind the corresponding connection line of the wheel contact points such that (a) in a first adjustment, the at least one connection element in front of the connection line of the wheel contact points has a very high transverse rigidity, and the at least one connection element behind the connection line of the wheel contact points has a very low transverse rigidity, and (b) in a second adjustment, the at least one connection element in front of the connection line of the wheel contact points has a very low transverse rigidity, and the at least one connection element behind the connection line of the wheel contact points has a very high transverse rigidity.
As a result of the distance of the connection elements from the connection line of the wheel contact points of the wheels of an axle, a lever arm is created which, during cornering, causes a deformation of the chassis frame in the sense of a slight bending in a plane parallel to the road. The self-steering behavior of the motor vehicle is influenced by the deformation of the chassis frame and the accompanying reaction with respect to the front and/or rear axle of the motor vehicle. In the case of the motor vehicle known from EP 0 868 338 B1, the self-steering behavior is fixedly predefined by the position of the connection elements. A change of the self-steering behavior is therefore not possible.
According to the invention, at least one connection element in front of as well as behind the connection line of the wheel contact points of the front wheels and/or of the rear wheels is provided, in which case the connection elements can in each case be changed in their transverse rigidity. As a result, the connection point between the vehicle body and the chassis frame can be quasi-displaced, so that the lever arm for the application of the centrifugal force introduced by the vehicle body will change and the self-steering behavior of the motor vehicle can thereby be influenced.
The connection elements are preferably constructed to be switchable between the “very high transverse rigidity” and the “very low transverse rigidity” conditions. As a result, a back-and-forth switching can take place at the corresponding axle between a position of the at least one connection element in front of or behind the connection line of the wheel contact points, with a corresponding effect on the self-steering behavior.
If connection elements with a changeable transverse rigidity are provided at the front axle as well as the rear axle of the vehicle, preferably these being connection elements where a switching over can take place between the “very high transverse rigidity” and the “very low transverse rigidity” conditions, it becomes possible to influence the self-steering behavior in a very complex manner.
For influencing the self-steering behavior, the transverse rigidity of the connection elements is of decisive significance.
The connection elements preferably not only have the task of transmitting transverse forces but also of transmitting longitudinal and/or vertical forces. For this purpose, at the concerned axle, the at least one front connection element as well as the at least one rear connection element is designed such that it alone is in each case capable of ensuring a connection between the vehicle body and the chassis frame that is functionally perfect in all operating positions of the motor vehicle. In an advantageous embodiment of the invention, the connection elements may be constructed such that, in addition to the transverse rigidity, by way of a corresponding triggering of the connection elements, a change of the longitudinal and/or vertical rigidity is also achieved. As a result, for example, the driving comfort (tread comfort) can be influenced.
As an alternative, different groups of connection elements may be provided for the transmission of horizontal forces (particularly transverse forces), on the one hand, and vertical forces, on the other hand. By means of such a constructional separation, it becomes possible to influence the self-steering behavior of the motor vehicle by use of only one connection element respectively in front of and behind an axle, which connection element is variable in its transverse rigidity.
According to the above-indicated further developments of the invention, the connection elements are constructed as switchable elements which, as required, can be triggered in intermediate conditions.
In a preferred embodiment of the invention, the connection elements act without applying an active adjusting path and thereby quasi-operate without any path.
In an alternative further development of the invention, connection elements are used which can apply an adjusting path and/or an adjusting angle. By means of such “active” connection elements, for example, the yaw angle of the vehicle body can be influenced during a cornering of the motor vehicle such that the yaw angle of the vehicle body is smaller than the yaw angle of the chassis frame. This smaller “turning-in” of the vehicle body with respect to the chassis frame results in a particularly agile vehicle behavior, for example, during a slalom-type drive of the motor vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.